[gemologist]

Well, I have been fooling around with my toys of late and stumbled upon a foolproof method of determining whether a pearl is bead nuclated or not.

And that method is... a laser!

A green laser to be specific. 5MW should do the trick, shoot the bean in at an oblique angle towards where you suspect the edge of the bead to be, and you will have your answer, it will show up as an outline.

It's really that simple, but takes a little patience, because most angles will not show the bead, a 10MW laser should do a better job, but I don't have one of those yet.

When I get around to it, I will post some pics of the bead with the laser.

I first found this out while looking at my coin pearls, because I prefer non bead nuked one... and Bummer to me, they are... oh well.

Oh, and MORE fun with lasers, you can see inside the pearls to about 3mm, so you can see inperfections that are hidden below the surface.

I have about 30 pounds of pearls here with me and I have been having endless fun looking at their insides.

[jshepherd]

Cool trick But I am afraid you are going to discover that on ALL your coin pearls. They are beaded as a rule. If not, they are button. This is the only size implant that will fit between the mantle and the shell when the mussel is young so it is often the first graft pearl.

[gemologist]

Here is one that kinda showed up, boy is it hard to get a shot of this.

this is one of my coin pearls

[DrTKStern]

Originally Posted by jshepherd

Cool trick But I am afraid you are going to discover that on ALL your coin pearls. They are beaded as a rule. If not, they are button. This is the only size implant that will fit between the mantle and the shell when the mussel is young so it is often the first graft pearl.

Fascinating! Have you tried your laser and taken pictures on a non-bead nucleated pearl? If so, please post that photo so we can see the comparison.

Have you ever tried it on a large natural ocean pearl? Where can I buy one of these devices?

Many thanks,
Tom Stern,MD

[john675]

Very cool - that would answer a lot of questions that show up here. It would also be a much more simple (compared to X-rays).

It's real cheap technology too (assuming this is what you mean):
http://www.dealextreme.com/details.dx/sku.91
http://www.amazon.com/PhotonTM-SUPER.../dp/B0002M65NM

Here's a 10mW version:
http://www.highlasers.com/10mW-Green-Lasers.html

[jerin]

Hi,

as laser pointers are dangerous for the eyes and other parts of the body I wonder whether a laser with 1MW instead of 5 MW or even 10 MW would be enought to check wheter the pearls are bead nucleated?

[gemologist]

No, a 1 mw laser wouldn't penetrate the nacre. Here is a shot of a really large FW pearls that is not nuked (about 28mmx10mm)

[gemologist]

Very cool - that would answer a lot of questions that show up here. It would also be a much more simple (compared to X-rays).

It's real cheap technology too (assuming this is what you mean):
http://www.dealextreme.com/details.dx/sku.91

--

Yeah, that one is the laser I use, it's so awesome it's hard to put into words. of course all my toys say they aren't really toys, like my power tools and my NDFeB magnets, but you can get yourself killed in all sorts of innocous ways, so I don't mind the apparent risk.

[Valeria101]

What if someone wanted to check nacre thickness with the toy? Feasible?

[gemologist]

I think so, but I havent tried on any SW pearls yet. I imagine it would be kinda like grading, you have to see alot of them before you get to the pint of being able to determine stuff like that for certian.

[DrTKStern]

Originally Posted by gemologist

I think so, but I havent tried on any SW pearls yet. I imagine it would be kinda like grading, you have to see alot of them before you get to the pint of being able to determine stuff like that for certian.

After reading your post and studying the photo, I found a 10MW green laser online for $129 and hope it arrives tomorrow. Technique-wise, are you in a darkened room with a mirror below the pearl? Is there heat that might crack the pearl?

As soon as I can, I'll send photos comparing similar sizes of a natural ocean pearl, a bead cultured saltwater pearl, and a non-bead cultured saltwater pearl, each with individual GIA opinions made by using a $500,000 digital x-ray, plus other equipment. In the field examining pearls, this would be a HUGE, HUGE help; and thanks for the lead.

Again, many thanks.
Tom Stern,MD

[knotty panda]

Originally Posted by gemologist

No, a 1 mw laser wouldn't penetrate the nacre. Here is a shot of a really large FW pearls that is not nuked (about 28mmx10mm)

It looks as though this shot is not at an angle. Is that true?

[smetzler]

Originally Posted by DrTKStern

this would be a HUGE, HUGE help

If this works then all it would take is a courageous high-profile appraiser or two to begin using it and the rest is history.

[jerin]

Hi Gemologist,

was there instructions together with the laser pen? If not please let us know what we should need to know not to hurt ourselves or the pearls. What distance to the pearl? Dark room? Protection for the eyes needed? Any other precautions?

[gemologist]

At 5MW, there is no chance of eye damage unless you are pointing the laser at your eye or staring into the reflection of it for an extended period, with 10MW some precautions would be advisable, like only looking for a short amount of time. Don't ever ever point a green laser at your eye, (or at a passing plane, they get a little wierd about that, especially the military jets)

I am finding all sorts of diagnostic uses for lasers in pearls because it penetrates where normal light does not, it becomes only a matter of time an practice until this diagnostic method can be conclusive and perhaps even normalized. I wish I had them back at GIA, because I am finding that this laser also highlights inclusions in every type of gemstone, it is a HUGE help in plotting, and even in cutting diagnostics.

As far as having instructions with the laser, I don't think it really did, but I don't think it is made for much more than pointint out stars or having fun with low-lying clouds

I prefer a darker room, but I don't see that as absolutly nessicary, in fact, if we are going to compare diagnostic machines to one another, I would find using lasers much easier than using a spectrometer (although they do different things) so, anyone I think, with time and practice can make calls as far as nucliated or non-nucliated.

As far as cracking the pearls, I would say that up to and probably exceeding 10MW for even an extended time should be fine, but approaching 20-25 MW there might be a possibility of damage. Actually, I am going to find someone with a really high end laser and ask them to help me, I will get them some loose pearls to see if they damage them at say 50 or 100MW

Actually, I know a high profile appraiser, I should tell him about this.